1. Field of the Invention
The present invention relates to an electrostatic chuck with a heater, which is for use in a manufacturing process of a semiconductor device, and the like, and to a manufacturing method of the electrostatic chuck with a heater.
2. Description of the Related Art
Heretofore, in the case of manufacturing a semiconductor device and the like, surface treatment such as deposition and etching has been implemented for a semiconductor wafer. As one of apparatuses that hold the semiconductor wafer during the surface treatment, there is an electrostatic chuck. The electrostatic chuck has a substrate mounting surface on which a substrate such as the semiconductor wafer is mounted. The electrostatic chuck holds the substrate on the substrate mounting surface by electrostatic force generated on the substrate mounting surface. In the electrostatic chuck, there is an electrostatic chuck of a type using Coulomb force as the electrostatic force. Moreover, as a type of this electrostatic chuck, there is an electrostatic chuck with a heater, which includes the heater, and heats up the semiconductor wafer.
A typical example of such a Coulomb-type electrostatic chuck with a heater includes a base made of ceramics. In the base, there are provided: an electrostatic chuck electrode (hereinafter, referred to as an “ESC electrode”) for generating the electrostatic force between the electrostatic chuck and the substrate mounted on the substrate mounting surface; and a resistance heating body for heating up the substrate. Moreover, an upper surface of the base is formed into the substrate mounting surface on which the substrate such as the wafer is mounted. Then, a portion from the ESC electrode to the substrate mounting surface in the base is formed as a dielectric layer, and a portion from the ESC electrode to a lower surface of the base is formed as a support member (for example, refer to Japanese Patent Laid-Open Publication No. H11-12053 (published in 1999)). The Coulomb-type electrostatic chuck is one to suck the substrate by using electrostatic suction force (Coulomb force) generated between the substrate mounted on a surface of the dielectric layer of the electrostatic chuck, that is, on the substrate mounting surface, and the ESC electrode of the electrostatic chuck.
In the Coulomb-type electrostatic chuck with a heater, aluminum nitride has been used for the ceramics of the base (for example, refer to Japanese Patent Laid-Open Publication No. H11-12053 (published in 1999) mentioned above).
In the conventional electrostatic chuck with a heater, in which aluminum nitride has been used for the ceramics of the base, volume resistivity of the dielectric layer is small, and accordingly, there has been an apprehension that a detachment response for the substrate mounted on the substrate mounting surface may be decreased.
Accordingly, it is considered to apply alumina higher in volume resistivity and also in corrosion resistance than aluminum nitride. In this case, for the resistance heating body, it is preferable to use niobium (Nb) and the like, which are similar in thermal expansion coefficient to alumina. However, when the resistance heating body contains niobium (Nb), there has been an apprehension that a niobium component of the resistance heating body is diffused into the support member in which the resistance heating body is embedded. The niobium component is diffused into the support member, whereby resistance characteristics of the resistance heating body are changed, and accordingly, there has been an apprehension that a malfunction occurs, that heating performance for the substrate, which should be uniform, is varied.
Moreover, in the electrostatic chuck, the suction force for the substrate is increased as a voltage applied to the ESC electrode is becoming higher; however, there has been an apprehension that a high voltage of approximately several thousand volts, which becomes necessary in the electrostatic chuck using the Coulomb force, may cause a dielectric breakdown and the like.
In this connection, it is an objective of the present invention to provide an electrostatic chuck with a heater, which enhances the detachment response for the substrate mounted on the substrate mounting surface, does not cause the dielectric breakdown even if the suction force is increased by being applied with the high voltage, and can uniformly heat up the substrate, and to provide a manufacturing method of the electrostatic chuck with a heater.